i40e: avoid disable of interrupt when changing ITR

The call to irq_dynamic_disable was turning off the interrupt completely
when trying to set ITR to 0 (for lowest moderation).  Just remove the
call as setting the values to 0 later in this function will suffice.

Change-ID: I47caf1ecbe65653cf63ec833db93094cd83fd84d
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Patrick Lu <patrick.lu@intel.com>
Tested-By: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -1574,7 +1574,6 @@ static int i40e_set_coalesce(struct net_device *netdev,
 		vsi->rx_itr_setting = ec->rx_coalesce_usecs;
 	} else if (ec->rx_coalesce_usecs == 0) {
 		vsi->rx_itr_setting = ec->rx_coalesce_usecs;
-		i40e_irq_dynamic_disable(vsi, vector);
 		if (ec->use_adaptive_rx_coalesce)
 			netif_info(pf, drv, netdev,
 				   "Rx-secs=0, need to disable adaptive-Rx for a complete disable\n");
@@ -1589,7 +1588,6 @@ static int i40e_set_coalesce(struct net_device *netdev,
 		vsi->tx_itr_setting = ec->tx_coalesce_usecs;
 	} else if (ec->tx_coalesce_usecs == 0) {
 		vsi->tx_itr_setting = ec->tx_coalesce_usecs;
-		i40e_irq_dynamic_disable(vsi, vector);
 		if (ec->use_adaptive_tx_coalesce)
 			netif_info(pf, drv, netdev,
 				   "Tx-secs=0, need to disable adaptive-Tx for a complete disable\n");